The present invention relates to a circuit package for electrical components which facilitates both internal and external connection of the circuitry contained therein as well as the dissipation of heat. The package also exposes control elements such as adjustable potentiometers, power terminals, and auxiliary terminals, on one side of the package while providing a heat sink on the other side, thereby facilitating the mounting of the package in an enclosure or other suitable mounting arrangement. In these respects, the circuit package of the present invention represents a substantial improvement over prior art packages such as that shown in U.S. Pat. No. 3,805,117.
Briefly, the circuit package of the present invention has a receptacle-like housing of plastic or other insulating material. The receptacle has a base plate with a depending peripheral wall. An upper substrate is positioned on the underneath side of the base plate and includes film circuits and other elements on its lower side. A lower substrate with film circuits and other elements facing the upper substrate closes the peripheral wall and forms a heat sink for the circuitry. Typically the circuitry on the lower substrate will comprise power circuitry.
Power input and output lead frame extensions extend from the lower substrate and protrude through terminal openings within the upper surface of the base plate of the housing. In like manner, lead frame extensions of the upper substrate also protrude through the terminal openings within the upper surface of base plate. In certain instances, a lead frame extension within a base plate opening is removably joined to a terminal plug for an external electrical connection. In other instances, lead frame extensions from both the upper and lower substrates are located within a common base plate opening and are joined for forming an electrical connection between the upper and lower substrate circuits and possibly to a terminal plug for an external electrical connection.